Sci-math: applications la proportional problem solving, by Madeline P. Goodstein. (Modules 1 and 2 with teacher’s guides.) Pp 100 each (approx). £2·95 (module 1), £3·50 (module 2), £5·50 each (guides). 1983. ISBN 0-201-20072-4/20073-2/20074-0/20075-9 (Addison Wesley)